1. Field of the Invention
The present invention relates to a vacuum cleaner, and in particular to a multi-cyclone dust separating apparatus, which is employed in a vacuum cleaner so as to filter dust suctioned from a surface to be cleaned together with air, using centrifugal force over two or more steps.
2. Description of the Related Art
In general, a vacuum cleaner comprises a bottom brush for suctioning dust from a surface to be cleaned together with air, a motor driving chamber provided with a driving source, and a vacuum cleaner body provided with a cyclone collection apparatus.
The cyclone collection apparatus is constructed in such a way that dust containing air, which is introduced from the bottom brush, is caused to form a swirling stream, so that dust is separately collected from the air by centrifugal force, and clean air is discharged into the motor driving chamber. In recent years, in order to improve dust collection efficiency, there has been proposed a multi-cyclone dust separating apparatus that separates dusts contained in air over two or more steps or more, wherein such a multi-cyclone dust separating apparatus comprises one or more secondary cyclones.
The above-mentioned types of conventional multi-cyclone dust separating apparatus are disclosed in WO02/067755 and WO02/067756 (Dyson Ltd). However, such conventional multi-clone dust separating apparatus have a disadvantage in that that because an upstream cyclone (a first cyclone), and a downstream cleaner (a second cyclone) are vertically arranged, thereby increasing the entire height of the dust-collection apparatus, they are mainly applied to an upright-type cleaner but hard to be applied to a canister-type cleaner. In addition, since the entire air flow path is long in the cyclone dust separating apparatus, there is a problem in that a loss in suction force of a driving source is high.
In order to solve the above-mentioned problems, the applicant developed a multi-cyclone dust separating apparatus (Korean Patent Application No. 2003-62520) as shown in FIG. 1. As shown the drawing, a multi-cyclone dust separating apparatus 10 comprises a cyclone body 20 with a first cyclone 30 and a second cyclones 40 being arranged around the periphery of a first cyclone 30, a cover unit 60 fitted on the top of the cyclone body 20, and a dust collection bin 70 connected to the bottom of the cyclone body 20. The cyclone body 20 is provided with an air inflow port 21, so that ambient air introduced into the first cyclone 30 passes through the cyclone body 20, and the cyclone cover 60 is provided with an air outflow port 62 through which purified air is discharged. Such a multi-cyclone dust separating apparatus 10 has an effect of increasing the dust collection efficiency because the plurality of second cyclones 40 are arranged around the first cyclone 30.
However, as shown in FIG. 1, the multi-cyclone dust separating apparatus 10 is configured in such a way that the ambient air is introduced into the top of the first cyclone 30 and then discharged to the top. In other words, the introduced air first flows downwardly (arrow B), then reverses direction and flows upwardly (arrow C), then escapes the upper portion of the first cyclone 30 via a grill member 80, and then flows into the second cyclones 40. Like this, there is a problem in that the air flow path from the introduction of air into the multi-cyclone dust separating apparatus 10 to the discharge of air out of the multi-cyclone dust separating apparatus 10 is still too long.
In addition, although the above-mentioned multi-cyclone dust separating apparatus 10 can be reduced in overall height as compared to the prior art, efforts for reducing heights of dust separating apparatus have been continued so as to miniaturize cleaners.